docs: def _get_magnitude_term(self, C, mag):
          """
          Returns the magnitude scaling term - equation 3
          """
          if mag >= self.CONSTS["Mh"]:
              return C["e1"] + C["b3"] * (mag - self.CONSTS["Mh"])
          else:
              return C["e1"] + (C["b1"] * (mag - self.CONSTS["Mh"])) +\
                  (C["b2"] * (mag - self.CONSTS["Mh"]) ** 2.)